Device For Manoeuvring An Aerodynamic Flap

Abstract

A device for manoeuvring an aerodynamic flap arranged on a motor vehicle, characterised in that it includes mechanical ways for shifting the flap from a retracted position to a deployed position, successively performing a movement extending the flap while keeping the plane of the flap parallel to the direction of an air stream flowing around the flap when the vehicle is moving, such that the aerodynamic pressure exerted on the flap is substantially zero, and then a movement pivoting the flap about a pivot axis located in a plane of the flap and passing substantially through a centre of aerodynamic thrust of the flap, such that the torque applied to the pivot axis and resulting from the aerodynamic forces is substantially zero. The shift from a deployed position to a retracted position is carried out by performing said movements in reverse order.

1 . A device for maneuvering an aerodynamic flap arranged on a motor vehicle, wherein the device comprises a mechanical device for causing the flap to pass from a retracted position to a deployed position, by performing movements in a given order of:
 extending the flap while keeping a plane of the flap parallel to a direction of an air flow circulating around the flap when the vehicle is moving, such that an aerodynamic pressure exerted on the flap when the vehicle is moving is substantially zero, then   pivoting the flap about a pivot axis situated in the plane of the flap and passing substantially through a center of aerodynamic thrust of the flap, such that a torque applied on the pivot axis and resulting from the aerodynamic pressure exerted on the flap when the vehicle is moving is substantially zero,   And the flap is configured to pass from a deployed position to a retracted position by performing said movements in reverse of the given order.   
     
     
         2 . The maneuvering device as claimed in  claim 1 , in which the mechanical device comprises a secondary rotation axis which is parallel to the pivot axis and about which are articulated a first rocker, which is connected to the aerodynamic flap by a first link rod and of which a change of position of the first rocker brings about the extending or retracting movement of the flap, and a second rocker, which is connected to the flap by a second link rod and of which a change of position of the second rocker brings about the pivoting movement of the flap. 
     
     
         3 . The maneuvering device as claimed in  claim 2 , in which the first and second link rod are attached, by first and second articulations respectively arranged at both ends of each of the link rods and whose axes are parallel to the pivot axis, to a face of the flap on the one hand and to said rockers on the other, and in which projections, on a plane perpendicular to the pivot axis, of the axes of said articulations are substantially arranged at the four corners of a deformable parallelogram. 
     
     
         4 . The maneuvering device as claimed in  claim 3 , in which:
 the first link rod is connected to the flap by its first articulation, whose axis is coincident with the pivot axis, and to the first rocker by its second articulation, whose axis is coincident with the secondary rotation axis, such that the first link rod pivots about the secondary rotation axis when the first rocker changes position,   the second link rod is connected to the second rocker by its second articulation arranged radially at a given distance from the secondary rotation axis, and to the flap by its first articulation arranged at the given distance from the pivot axis of the flap.   
     
     
         5 . The maneuvering device as claimed in  claim 4 , in which the positions of the link rods are set up such that a plane passing through the secondary axis and through the axis of the articulation of the second link rod on the second rocker is substantially parallel to the plane of the flap. 
     
     
         6 . The maneuvering device as claimed in  claim 2 , in which the mechanical device comprises a drive wheel driven in rotation about a main axis parallel to the axis pivot, at least one face of the disk formed by the drive wheel having a pin for moving the first and second rockers in rotation from one position to another and vice versa. 
     
     
         7 . The maneuvering device as claimed in  claim 6 , in which each rocker comprises a radial slot in which circulates a pin for causing said rocker to pivot from one position to another about the secondary rotation axis. 
     
     
         8 . The maneuvering device as claimed in  claim 7 , in which the drive wheel comprises at least one circular blocking disk which rotates about the main axis and is arranged in elevation on each of the faces of the disk formed by the drive wheel having a pin, of which the radius is less than the distance to the main axis of said pin, and placed opposite at least one rocker. 
     
     
         9 . The maneuvering device as claimed in  claim 8 , in which the drive wheel comprises two blocking disks, each arranged on one of the faces of the disk formed by the drive wheel, each of these faces having a pin, and in which the rockers are arranged in line with each of the blocking disks on either side of the disk formed by the drive wheel. 
     
     
         10 . The maneuvering device as claimed in  claim 8 , in which each rocker comprises two semi-circular cutouts respectively defining a first and a second position of the rocker, arranged on either side of the radial slot, each semi-circular cutout having a radius equal to the radius of the blocking disk opposite which said rocker is placed. 
     
     
         11 . The maneuvering device as claimed in  claim 10 , in which, when a rocker is placed in a position, the center of a semi-circular cutout is arranged on the main axis such that said rocker is blocked in rotation by the blocking disk opposite which said rocker is placed. 
     
     
         12 . The maneuvering device as claimed in  claim 11 , in which, when the first and second rocker are each placed in a given position, a torque applied to the main rotation axis and resulting from forces exerted on the flap is zero. 
     
     
         13 . The maneuvering device as claimed in  claim 8 , in which each blocking disk has a recess arranged radially in line with the pin, so as to permit the pivoting of the rocker when the pin changes position. 
     
     
         14 . The maneuvering device as claimed in  claim 3 , in which:
 the flap is in the retracted position when the first rocker is in a first position,   the flap is in the extended position when the first rocker is in a second position.   
     
     
         15 . The maneuvering device as claimed in  claim 3 , in which:
 the flap is parallel to air flow circulating on a bodywork element supporting the flap when the vehicle is moving, when the second rocker is in a first position,   the flap is in the pivoted position when the second rocker is in a second position.   
     
     
         16 . The maneuvering device as claimed in  claim 14 , in which, when the drive wheel travels over an angular path of less than 360°, respective arrangements of the rockers and the pins are adjusted angularly about the main axis such that the change of position of the first rocker takes place when the second rocker is arranged in the first position, and such that the change of position of the second rocker takes place when the first rocker is arranged in the second position. 
     
     
         17 . The maneuvering device as claimed in  claim 6 , in which the drive wheel is rotated under the action of a motor coupled to a geared motor. 
     
     
         18 . The maneuvering device as claimed in  claim 9 , in which each rocker comprises two semi-circular cutouts respectively defining a first and a second position of the rocker, arranged on either side of the radial slot, each semi-circular cutout having a radius equal to the radius of the blocking disk opposite which said rocker is placed.